Catheter apparatus are used for many purposes, including administering intravenous fluids and drugs, and are especially useful in the cardiovascular field. Ultrasonic cardiac catheter apparatus have been patented as is evident from prior art patents. Exemplary of patents concerning ultrasonic cardiac catheter apparatus are:
______________________________________ U.S. Pat. No. Inventor Date of Issue ______________________________________ 4,545,390 James J. Leary Oct. 08, 1985 4,582,067 Fred E. Silverstein, et al. Apr. 15, 1986 5,000,185 Paul G. Yock Mar. 19, 1991 5,002,059 Robert J. Crowley, et al. Mar. 26, 1991 5,109,859 Ronald D. Jenkins May 05, 1992 5,354,220 Dipankar Ganguly, et al. Oct. 11, 1994 5,505,088 P. Anthony N. Chandraratna, et al. Apr. 09, 1996 5,513,639 Gengi Satomi, et al. May 07, 1996 5,546,947 Hiroyuki Yagami, et al. Aug. 20, 1996 5,570,693 Yue-Teh Jang, et al. Nov. 05, 1996 ______________________________________
A brief description of the listed prior art patents follows: U.S. Pat. No. 4,582,067 teaches a catheter apparatus and method including an ultrasonic probe for introducing an ultrasonic field into arteries. The method includes monitoring a Doppler signal to obtain blood flow data. U.S. Pat. No. 4,545,390 teaches a guide wire and dilation catheter combination for use in coronary angioplasty techniques. The apparatus includes lumen means for delivering liquids and delivering air to inflate a balloon. The external end includes a Y-fitting for coupling to liquid or air sources. U.S. Pat. No. 5,000,185 teaches, in one embodiment, a catheter apparatus comprising a tubular element having at least four (4) lumens and an ultrasonic transducer. The catheter is provided in various sizes. The schematic of FIG. 6 provides an overview of the system. The apparatus uses piezoelectric crystal oscillators and disclose the use of other means. A cutter device 29 is employed in the apparatus. U.S. Pat. No. 5,002,059 teaches an ultrasound catheter device comprising a catheter sheath, an elastomeric septum which contains ultrasonic transmission fluid such as sterile water or saline solution. U.S. Pat. No. 5,109,859 teaches a laser angioplasty catheter for use in removing atherosclerotic plaque from coronary arteries. The device includes an ultrasound transducer, a balloon and a fiber optic waveguide for receiving laser energy. U.S. Pat. No. 5,190,046 teaches an ultrasound imaging balloon catheter apparatus including an ultrasound transducer, catheter and balloon arrangement. U.S. Pat. No. 5,320,106 teaches an intracavitary diagnosing apparatus including a transducer and an ultrasonic mirror for directing ultrasound into an organ. U.S. Pat. No. 5,354,220 teaches an electrical coupler for coupling an ultrasonic transducer to a catheter. The catheter coupler interfaces with a control and processing system, as shown in FIG. 7. U.S. Pat. No. 5,505,088 teaches an ultrasound microscope means including an ultrasound transducer means for transmitting an receiving ultrasound for imaging living tissues. U.S. Pat. No. 5,546,947 teaches an ultrasonic endoprobe having a metal tube made from a superelastic material. The metal tube encloses an ultrasonic transducer. The apparatus has utility in examination of hollow organs or parts of a living body. U.S. Pat. No. 5,513,639 teaches an ultrasonic diagnostic probe for use in imaging body cavities. The probe includes an inflatable balloon member having space for carrying an array of piezoelectric elements. U.S. Pat. No. 5,570,693 teaches an intravascular ultrasound imaging apparatus. The apparatus comprises a catheter body and a transducer that ultrasonically scans the vessel to create an image. The apparatus also includes a cutter for performing atherectomy.
The foregoing patents primarily teach the use of ultrasonic devices and method for imaging of blockages in vessels, but do not teach, suggest or motivate apparatus and method that uses sound waves selected to resonate at selected required sound frequencies to liquidize the solid obstruction in a cardiac vessel.
Accordingly, it is a primary object of the present invention to provide an ultrasonic cardiac catheter apparatus and method that uses sound waves selected to resonate at selected required sound frequencies to liquidize the solid obstruction in a cardiac vessel.
A related object of the present invention to provide an ultrasonic cardiac catheter apparatus and method that combines the imaging attributes of the ultrasonic catheter apparatus in combination with attributes that uses sound waves selected to resonate at selected required sound frequencies to liquidize the solid obstruction in a cardiac vessel.